A liquid crystal display (LCD) device includes a backlight driver circuit that often uses a backlight driver integrated circuit (IC) to adjust backlight brightness. The backlight driver IC itself has a temperature protection function: when normal operation of the backlight driver IC is affected because of an increase in temperature of the backlight driver IC, the backlight driver IC automatically enters a protection mode to reduce the backlight, brightness or directly stop operation, which increases service life of the backlight driver circuit. However, there are higher failure rates in typical backlight driver circuit, malfunctions such as dimming function, no backlight output occur when the backlight driver circuit is used for a period of time. If there is no problem in the backlight driver IC, however, when the temperature of the backlight driver IC drops below a protection temperature, the malfunctions may still exist which affects service life of the backlight driver circuit.